U.S. Pat. No. 4,130,331 discloses an electrical terminal and a terminal housing for establishing an electrical contact with insulated wires, particularly wires having thin varnish type insulating coatings such as polyvinyl formal resin coatings which are used for coil windings. The terminal of the above identified U.S. Patent comprises a pair of plate-like members in side-by-side parallel relationship which are connected at corresponding ends by an integral bight. An opening is provided in the bight and wire-receiving slots extend inwardly in the plate-like sections from the opening. The housing has a terminal receiving cavity. Aligned wire-admitting slots in the housing permit placement of a wire in the wire-admitting slots with an intermediate portion of the wire extending through the cavity. A wire supporting surface is provided in the cavity which supports the wire and is dimensioned to enter the opening in the bight. Electrical contact to the wire is established by placing the wire in the wire-admitting slots and then inserting the terminal into the cavity so that the wire is received in the wire-receiving slots of the terminal.
Terminals and terminal housings of the general type disclosed in U.S. Pat. No. 4,130,331 have been widely adopted in the electrical industry for making electrical connections to wires, particularly wires extending from electrical coils. In most instances, the terminals and housings have been dimensioned and designed to make electrical contact with AWG30 wires (having a diameter of 0.25 mm) or wires more coarse than AWG30. It has been found to be impractical to exploit the principles of the invention discussed in U.S. Pat. No. 4,130,331 in making electrical connections to wires finer than AWG30 wires. Wires finer than AWG30 are relatively flimsy and it has been found to be impractical to produce a wire-receiving slot in the terminal which will accept the wires and establish electrical contact without shearing the wire or damaging it to the extent that the resulting electrical connection is not reliable. It would be desirable to apply the principles of the invention of the above identified patent to AWG40 or 41 wires, for example. An AWG41 gauge wire, however, has a diameter of 0.07 mm and the varnish type insulation on a wire of this gauge is 0.01 mm or less. It can be readily appreciated then that an AWG 41 gauge wire is extremely delicate and must be handled with great care and finesse when an electrical connection is being made thereto in order to avoid breaking of the wire while the connection is being made. The present invention is directed to the achievement of an electrical terminal and a terminal housing which is effective to establish contact with wires as fine as AWG41 gauge as well as wires of a more coarse gauge.
The invention comprises an electrical terminal and a terminal housing, the terminal being of the type comprising first and second plate-like members in side-by-side relationship which are joined at corresponding ends by an integral bight. A wire-receiving slot extends into the bight and partially along the length of the terminal. The housing has a terminal receiving end and first and second external sidewalls extending from the terminal receiving end. A terminal receiving cavity extends inwardly from the terminal receiving end and has opposed first and second cavity sidewalls which are proximate to the first and second external sidewalls respectively. First and second wire-admitting slots extend inwardly from the terminal receiving end, the first wire-admitting slot intersecting the first external sidewall and the first cavity sidewall, the second wire-admitting slot intersecting the second external sidewall and the second cavity sidewall. A wire supporting surface is provided in the cavity for supporting a wire positioned in the wire-admitting slots with a portion of the wire extending through the cavity. The terminal and housing are particularly characterized in that a rib is provided in the cavity which is spaced from the second cavity sidewall and proximate to the first cavity sidewall. One end of the rib is adjacent to the inner end of the first wire-admitting slot and the wire supporting surface is on the one end of the rib. The rib extends further into the cavity and has a side surface portion which is spaced from, and extends alongside, the second cavity sidewall. The bight of the first plate-like member has a clearance opening therein which is dimensioned to receive the side portion of the rib. The distance between the side portion of the rib and the second cavity sidewall is sufficient slideably to receive the second plate-like member. The wire-receiving slot is provided in the second plate-like member so that upon placement of the wire in the wire-admitting slots and insertion of the terminal into the cavity, a portion of the wire which extends from the wire supporting surface to the second cavity sidewall is received in the wire-receiving slot.
In accordance with further embodiments, the rib is integral with the first cavity sidewall and the wire supporting surface is recessed inwardly from the one end of the rib, the rib having convergent wire guiding surfaces on each side of the wire supporting surface. In accordance with a further embodiment, the terminal comprises an elongated section of dual thickness material, the first plate-like section, the bight, and a major portion of the second plate-like section being of material of reduced thickness, the remainder of the second plate-like section being of relatively thicker material. In accordance with a further embodiment, the terminal is double ended and has a lead wire connecting member extending from the second plate-like member. In accordance with a further embodiment, the wire-receiving slot comprises a slit produced by shearing the second plate-like member.